Brake-shoe adjuster.



Patented July 29, I902.

I E. M. HERB. BRAKE SHOE ADJUSTER.

(Application filed Dec 7, 1901.\

(No Model.)

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UNITED STATES PATENT OFFICE.

EDWIN M. HERB, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF PITTSBURG, PENNSYL- VANIA, A CORPORATION OF PENNSYLVANIA.

BRAKE-SHOE ADJUSTER.

SPECIFICATION forming part of Letters Patent No. 705,927, dated July 29, 1902.

' Application filed December '7, 1901. Serial No. 85,051. (No model.)

To all whom it may concern.-

Be it known that I, EDWIN M. HERB, a citizen of the United States,residing in Pittsburg,

' county of Allegheny, State of Pennsylvania,

. have invented or discovered a certain new and useful Improvementin Brake-Shoe Adjusters, of which improvement the following is a specification.

My invention relates to adjusting devices for railway-brakes, and has for its object to provide a construction which will automatically compensate for the wear of the brakeshoe and maintain the distance substantially constant between the rail, wheel, or other friction-surface and the face of the shoe when supported in its normal release position.

With this object in view the invention consists in an adjustable support for the brakeshoe and means operated by the movement of the shoe for automatically adjusting its support when the shoe wears down to a certain point.

My invention is especially adapted to be employed in connection with that class of brake-shoes which have a certain amount of dragging movement when applied, such as a magnetic brake-shoe adapted to apply wheel shoes by a dragging or longitudinal movement with respect to the car.

In the accompanying drawings, Figure 1 is a side view of a combined rail and wheel brake, showing my improvement applied thereto; Fig. 2, a plan view, a part thereof being broken away to more clearly show my improvement; Fig. 3, a detail view on a larger scale, and Fig. 4 a side view showing my irnprovement applied to a magnetic wheel-shoe.

In the form of brake apparatus illustrated in Figs. 1 and 2 the wheel-shoes 2 are..sus-

pended by links 8, pivotally supported from the car-frame, and have levers 3 pivoted thereon, the lower ends of saidlevers being connected to the magnetic rail-shoe l by means of extensible push-bars & and the upper ends of the lovers being connected together by the rod 5. The rail-shoe is suspended j ust above the rail by springs 6, secured to a bracket 7, so that when the shoe is in its normal release position there is just sufficient clearance-space between the wearing-face of the shoe and the top of the rail. When the shoe is magnetized by sending a current of electricity through its coil, it is attracted to the rail and by its frictional resistance to the momentum of the car is subjected to a dragging or longitudinal movement, which, acting through the pushbars and levers, applies the wheel-shoes to the wheels.

As thus far described the construction does not constitute my. invention, but is substantially the same as that shown in Reissue Patent No. 11,786, November 7, 1899.

It is found in practice that as the shoe wears away and the clearance-space between it and the rail increases a greater current is required to energize the magnet sufficiently to bring it-into contact with the rail than is necessary to give the proper braking action and results in a sudden application of the brake-shoe with greater force than is desired. This seriously interferes with an easy and gradual application of the brakes, and in order to overcome this defect it is desirable that in its normalv position the brake-magnet should always be held in as close proximity to the rail as practicable, with only a sufficient clearance-space to pass switches, &c., along 'the track. In order to compensate for this wear and automatically adjust the position of the shoe, I have provided the adj usting-screws 15, which are threaded into the brackets 14:, secured to the rail-shoe, and have heads 17 rotatably mounted in the sockets 18, attached to the ends of suspension-springs 6, thus forming swivel joints therewith. The adj ustingscrews 15 are provided with projecting arms 16, adapted to engage fixed stop-pins 12 or 13 during the dragging movement when the shoe becomes worn down to acertain point. The stop-pins are carried by arms 10 and 11 of the bracket 9, which is secured to the car-frame, and they are located at the proper elevation on opposite sides of the adjusting-screw, so that as the shoe wears down thearms 16 will engage either stops 12 or 13, according to the direction the car is moving. In this way the screws are rotated and the shoe adjusted toward the rail, thus maintaining the clearancespace between the shoe and rail substantially constant. If there should be suliicient friction between the heads of the adj Listing-screws and their respective sockets to cause a partial rotation of the sockets against the torsional force of the springs at the time the screws are being adjusted, this may be prevented by the use of the rod 28, connecting the two socket-pieces, or by any other suitable means.

Fig. 4 illustrates my invention applied to a magnetic wheel-shoe of a brake apparatus such as is shown in my prior patent, No. 652,266, of June 26, 1900. In this construction the magnetic wheel-shoe 20 is provided with a lug 21, havinga threaded engagement with the adjusting-screw22,the head ofwhich is rotatably mounted in the cap 23 of the spring-supported rod 24. The spring 25 is supported on the car-frame, and the rod 24 may be pivoted thereto by a slot-and-pin connection to allow for the vertical and dragging movement of the magnetic shoe. The fixed stop-pins 26 and 27 are also supported from the frame and are located in the desired positions on opposite sides of the adjustingscrew. to engage the arms 29 and adjust the screw during the dragging movement of the brake-shoe in the direction of rotation of the Wheel. Suitable connections for applying other wheel-shoes by the dragging movement of the magnetic shoe may be used, as shown in my prior patent, above referred to.

While I have shown my patent applied to magnetic brake-shoes, it is not necessarily limited to such construction, but may also be employed in connection with various other forms of brake apparatus.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. The combination with a brake-shoe, of an adjustable support therefor, and means operated by the dragging movement of said shoe for adjusting said support.

2. The combination with a brake-shoe having an adjustable support, of another brakeshoe adapted to be applied by the dragging movement of the first shoe and means for automatically adjusting the said support to compensate for the wear of said shoe.

3. The combination with a brake-shoe having an adjustable support, of another brakeshoe adapted to be applied by the dragging movement of the first shoe when the car is moving in either direction, and means operated by the dragging movement for adjusting said support.

means for applying said shoe, of another brake shoe and intermediate connections adapted to apply the second shoe by the dragging movement of the first shoe, and means operated by such movement for automatically adjusting said support when the first brake-shoe becomes worn.

5. In a car-brake, the combination with a magnetic brake-shoe having an adjustable support, of means for automatically adj usting said support to compensate for the wear of said shoe.

6. In a car-brake, the combination with a magnetic brake-shoe having an adjustable spring-support, and means operated by the dragging movement of said shoe for adjusting said support.

7. In a car-brake, the combination of a brake-shoe, a support therefor having an adjustable screw to compensate for the wear of the shoe, and means operated by the dragging movement of said shoe for adjusting said "screw.

8. In a car-brake, the combination of a brake-shoe, a support therefor having an adj ustable screw, and fixed stops secured to the car-frame by which said screw may be rotated during the dragging movement of said shoe.

9. In a car-brake, the combination with a rail brake-shoe having an adjustable support,

of means operated by the dragging movement of said shoe for adjusting said support.

10. In a car-brake, the combination with a rail brake-shoe, having-an adjustable support, of a wheel-shoe adapted to be applied by the longitudinal movement of the railshoe, and means operated by said longitudinal movement for adjusting said support.

11. In a car-brake, the combination with a magnetic rail-shoe having an adjustable support, of means operated by the longitudinal movement of the rail-shoe for adjusting said support.

12. In a car-brake, the combination of a rail brake-shoe, an adjustable supportingscrew having projecting arms, and fixed stops for engaging said arms.

In testimony whereof I have hereunto set my hand.

EDWIN M. HERR. Witnesses:

S. O. MoOoNAHEY, FRANoIs L. CLARK. 

